Photovoltaic modules, as they are typically installed outdoors, must be constructed to withstand extremes in environmental conditions in order to continue to generate electricity reliably over a long period of time. Moreover, there are other design concerns specific to certain photovoltaic modules that use lenses to concentrate sunlight.
Photovoltaic modules can generate relatively high voltage and may need to be effectively insulated from their surroundings. Moreover, as solar modules are usually installed outside, the material may need protection from the elements such as water vapor, which may be especially important with thin film photovoltaics such as copper indium gallium di-selenide (CIGS) as this and similar photovoltaic materials and their electrical contacts are subject to degradation in the presence of water vapor. Also, as the photovoltaic material and concentrating lenses typically have significantly different coefficients of thermal expansion, there must be a means to accommodate their relative displacement vis-á-vis each other when a photovoltaic module is heated. To effectively harness the current that is produced by the photovoltaic material, a means may be necessary to draw the current off of the top of the photovoltaic material without excessive electrical resistance. Finally, a concentrating lens assembly should ensure optimum light transmission from the bottom of the concentrating lens to the photovoltaic and to minimize the amount of shading caused by a conducting grid on the surface of the photovoltaic.